Musk dismisses one of the main technical challenges of being on the Martian surface: the temperature.

A view from the ‘Kimberley’ formation on Mars taken by NASA’s Curiosity rover. The strata in the foreground dip towards the base of Mount Sharp, indicating flow of water toward a basin that existed before the larger bulk of the mountain formed.
NASA/JPL-Caltech/MSSSJuni 15, 2017